Abstract
A Field survey conducted in 2012 revealed the occurrence of olive knot disease in Nineveh Province. The highest infection rate and infection degree were 29% and 1.8 degree respectively in Al-Fadhiliya, while the lowest infection rate was 8.4% in Barima and lowest infection degree was 0.8 in Al-Shallallat. As for all the scanned areas in the province we observe that an average percentage of infection rate was 15.08% and infection degree was 1.2. Isolation and diagnosis of olive knot disease in Al-Fadhiliya resulted in that a single pure bacterial colonies caused by (Pss) bacteria. Pathogenicity test results on Baashiqi cultivar of olive trees cuttings revealed detection of knots. Screening of eight olive cultivars showed the variance of these cultivars in number and diameter of the knots in the first and second readings. The most susceptible cultivars were (Baashiqi, Manzilino, Arbequina and Ashrasi) the infection rate were (2.33, 2.30, 2.12, 2.10, 3.17, 2.90, 2.86, 2.83) respectively. These cultivars did not differ significantly. The less affected cultivars in the number of knots was (Sourani) where the infection rate was 0.70 and 1.00 knots, compared to (Khodeiri) type that showed no infection in both first and second readings. The disease affect in the knot diameter average showed that (Manzilino) was the most susceptible, because of developed knots to 10.19 and 12.41 mm for both readings respectively. Followed by (Baashiqi) 9.10 and 11.10 mm for both readings. The less average of knot diameter was (Sourani) cultivar share rate was 3.65 and 4.06 mm respectively both readings..
